1. Field of the Invention
The present invention relates to a radio frequency system and a password management method in the radio frequency system. More particularly, the present invention relates to a radio frequency system and a password management method in the radio frequency system using two types of passwords.
2. Description of the Related Art
A radio frequency system includes at least one storage device and at least one reader. Here, the storage device means a small-capacity storage device such as a smart card and a radio frequency identification (RFID) tag.
The smart card is a storage device that has a high security, high stability, and a mass storage capability, and its internal memory can be used in a divided manner. The smart card can be applied to diverse fields of services. Application fields using smart cards may include banking/settlement/distribution, information communication and mobile communication, medical welfare, access control, self-inspection of a meter, traffic fee collection, city complex card, and the like, and will be steadily extended in the future.
The RFID tag is a tag in the form of a thin plate that is typically read by an object in a non-contact manner through a radio signal. The RFID tag can be used in diverse application fields such as physical distribution, traffic, security, safety, and the like. Application services using the RFID tag may include a burglarproof device in a shopping center, security system such as speaking drugs for a blind person, forgery prevention device, animal tracking, vehicle safety device, private entrance/exit and access permission device, automatic fee collection system, production management, transport container freight tracking system, and the like. Also, the reader is a device that reads stored information by accessing a storage device as described above.
Here, the storage device requires the control of access and use of information stored in the storage device. That is, if access to information stored in the storage device is requested by an external reader, the storage device confirms whether an access authority for the information stored in the storage device exists in the reader that has requested the access, through the confirmation of the password transmitted from the reader.
Typically, the reader transmits a password required for accessing specified information to a storage device, and decides whether to permit access to the specified information of the reader through a process for confirming whether the transmitted password coincides with the password stored in the storage device.
However, as described above, the storage device may be a tag, which may be attached to a product that is circulated in the market. In this case, the corresponding product may be managed by different managers according to distribution stages and the respective managers attempt to access the storage device attached to the product through readers held by the respective managers.
According to a method for providing an authority to access information in a storage device to managers at respective distribution stages, a password for accessing information in the storage device can be shared by the respective managers. In this case, however, the corresponding password may leak. Also, previous managers who have no authority to manage the product any more can still access the information in the storage device by the previously allocated password.
Accordingly, there is a need for an improved radio frequency system that includes a password management method for accessing information in a storage device and preventing password leaks.